BS 3137:1972

Methods
1 General
1.1 Scope
1.2 Definitions
1.3 Principle
2 Determination of the bursting strength of paper
2.1 Apparatus
2.2 Calibration
2.3 Sampling and preparation of test pieces
2.4 Procedure
2.5 Calculation and report
2.6 Precision of results
2.7 Sources of error
3 Determination of the bursting strength of board
3.1 Apparatus
3.2 Calibration
3.3 Sampling and preparation of test pieces
3.4 Procedure
3.5 Calculation and report
3.6 Precision of results
3.7 Sources of error
Appendices
A The clamps (paper)
B Testing the clamping
C Clamping loads (paper)
D Gauge calibration
E Checking of hydraulic system
F The clamps (board)
G Clamping loads (board)
H Pneumatic burst test
Figures
1 Clamps (paper)
2 Expansion curves
3 Clamps (board)
4 Essential features of a pneumatically operated
     burst tester
5 Dimensions of area below upper surface of lower
     clamp of a pneumatically operated burst tester

Describes the hydraulic methods for determining the bursting strength of paper in the range from 70 kN/m² to 1100 kN/m² and for board within the range 350 kN/m² to 5500 kN/m². The pneumatic method, sometimes needed for pulp handsheets and weak papers, is described in an appendix.

This British Standard describes methods for measuring the bursting strengths of paper and board. Section 2 specifies a method for measuring the bursting strength of paper subjected to rising hydraulic pressure.

The method is applicable to paper with bursting strength within the range from 70 kN/m² to 1 100 kN/m². It should not, however, generally be used for the components (such as fluting medium or linerboard) of a combined board, for which the method specified in Section 3 is more suitable. Paper of bursting strength less than 70 kN/m² may also be tested by bursting a number of sheets together.

Section 3 of this British Standard specifies a method for measuring the bursting strength of board subjected to rising hydraulic pressure.

The method is applicable, in principle, to all types of board (including solid and corrugated fibreboard) with bursting strength within the range from 350 kN/m² to 5 500 kN/m^{2 1)}.

It may also be used for papers or boards with bursting strength as low as 250 kN/m² if the paper or board is to be used to prepare a material of higher bursting strength, such as corrugated board. In such instances, the measurements will not necessarily have the accuracy or precision stated for this method and the report should carry a note that the test gave results that were below the minimum value required by the method.

NOTE The titles of the British Standards referred to in this standard are listed on the inside back cover.